Apoptosis Induced By Combined Treatment With VP-16 and TNF-α and It's Relation to Expression of bcl-2 in Colon Cancer Cells

Objective To investigate the effect of combination VP 16 and TNF α on apoptosis and bcl 2 expression in SW480 human colon cancer cells.Methods The inhibitive effect of VP 16 and TNF α on SW480 was measured by MTT.Apoptosis of colon cancer cell was studied by TUNEL.The expression of bcl 2 gene was determined by immunohistochemical analysis.Results After treatment with 3 000 U/ml of TNF α and various concentrations of VP 16 for 48 h,MTT assay revealed a significant decrease of relative viability in compassion to the situation without treatment.Treatment with combination TNF α and VP 16 for 48 h resulted in a significant increase of nick end positive cells compared to treatment with TNF α or VP 16 alone( P 0.05),and the expression level of bcl 2 gene lowered significantly compared with the control group.Conclusion These results confirmed that combined VP 16 and TNF α could synergistically induce apoptosis in SW480 cells and decrease the expression level of bcl 2 gene.